Carotenoids exist widely in nature. Pigment of carbohydrates was firstly crystallized and separated from the carrot roots by Wachenroder in 1831 and named as “carotene”. After that, yellow polar pigment are separated and extracted from autumn leaves by Berzelius and named as “xanthophyll”. With the development of biophysical technology, a series of natural pigments are separated by chromatographic method and named as “carotenoid”. They have common chemical structural characteristics, and their molecular centers are all long chain of polyunsaturated polyisoprene. Many derivatives are produced by the means of cyclization, addition of oxygen or rotation of bond and isomerization. Currently, members of known carotenoids have about more than 600 species.
Carotenoid belongs to terpenoid compounds and is a generic name of two major categories of pigments as carotene and xanthophyl. Carotenoid of hydrocarbon race which molecules have not oxygen atoms are referred to as “carotenes”. Derivatives and esters thereof which molecules have oxygenic functional groups, such as hydroxy groups, epoxy groups, methoxyl groups and ketone groups, are referred to as “xanthophylls”.
There are hundreds of carotenoids existed in the nature, but there have six species to be common and relatively large amounts, such as β-carotene, astaxanthin, canthaxanthin, lutein, zeaxanthin and lycopene. With the development of biotechnology and synthesis technology, many species of the six carotenoids have many different origins, for example, β-carotene may be obtained by synthesis, and also by fermentation method or cultivating Dunaliella. and also by extracting from natural substances, such as palm oil. Lycopene may be obtained by extracting from tomatoes or fermentation, or also by synthesis. In these carotenoids, lutein is an exception. Currently, because of asymmetrical structure, lutein is only obtained by extracting from plant but not by high cost synthesis method.
These six carotenoids which have similar molecular structures are a kind of hydrocarbons and oxygenated derivatives thereof. They are composed of eight isoprenoid units and only have small differences in a six-member ring at two ends. There are many chromophoric groups with conjugated double bond in the molecular structure of carotenoids, which gives carotenoid a special absorption area (blue light area) in ultraviolet-visible light area. Accordingly, crystal or solution of carotenoid possesses very glorious red. orange or yellow color under visible light. The color varies with different concentration. Carotenoids are deemed as a kind of pigments for a long time. Autumn leaves and all sorts of colorful animals give people incomparable aesthetic feeling in nature. Meanwhile these conjugated double bonds also make carotenoid become a good free radical scavenger which has very strong activity of antioxidant and could effectively block free radical chain reaction in the cells. Thus, carotenoid has many kinds of special and important physiological functions.
β-carotene is the most wide and important carotenoids, and is a favorable provitamin A. According to the amount of Vitamin A in body, β-carotene could automatically decompose to supplement deficiency of Vitamin A. Lutein and zeaxanthin are isomers, and the only difference between them is the different site of a double bond on one of the six-member ring chain-terminating. They are only carotenoids existed in the human eye retina, and they are selectively deposited in the macular region and the whole retina, and their density is the highest around the central fovea of macula and gradually decreased around the retina. These macular pigments are able to effectively prevent from occurrence of oxidation reaction on the retina and have important protective effect on the retina. Lycopene has very good effects on prophylaxis and treatment of prostate disease. Astaxanthin also has important roles of anti-tumor and preventing cancer, etc. This is why lots of epidemiologic studies confirm that consuming fruits and vegetables containing carotenoid usually and regularly decrease the risk of chronic diseases including cardiovascular disease, and meanwhile have beneficial effects on prophylaxis of cancer.
Therefore, nutritionists highly recommend that addition or preventive intake of antioxidant such as vitamin and carotenoid. Food and pharmaceutical market provide consumers a great quantity of the kind of “cell protective agent”. Now various health foods added to single or many kinds of carotenoid are presented on the market, but the more effective means to supplement carotenoid for people is to intake in the form of dietary supplement, for example various tablets, hard capsules, soft capsules, etc. Usually only a grain of tablet or capsule can fulfill a day total requirement of carotenoid for one person. Concerning request of these intake way, many kinds of dosage forms of carotenoid are also presented on the market, for example microparticles CarolBeta® and CaroCare® rich in β-carotene suited to tabletting or covering hard capsules, microencapsulation beadlets CarolGold®, FloraGlo®, rich in xanthophyl, microparticle CarolZea® rich in zeaxanthin, microparticle Redivivo® rich in lycopene, etc; And there are some oil suspensions of carotenoid suited to cover soft capsules, but oil suspensions of these carotenoids especially natural carotenoids obtained with natural origins, such as by fermentation method or extracting from plant or algae often exist the following problems: oil suspensions have high fluidity but content of the effective component is low, oil suspensions have high content of carotenoid but have very high viscosity and poor fluidity.
Highly viscous carotenoid oil suspensions are less homogeneous and provide poor fluidity to the suspension, making the suspension undesirable as a filling in soft capsules. Although, heating can reduce the viscosity and increase the fluidity of the oil suspension, the additional step of heating results in an undesirable thermal and chemical degradation of carotenoids.
The main reason for causing oil suspensions poor fluidity is that some fat-soluble fibers and phospholipids are difficult to be removed in the process of carotenoid purification. These small amounts even traces of fat-soluble fibers and phospholipids make viscosity of oil suspensions of carotenoid increase more than ten times even to several hundred times and decrease the fluidity of product. However, there have not been disclosed about method of decreasing or removing small amounts of fat-soluble fibers and phospholipids existed in the natural carotenoid so far.
The present invention tried to decrease or remove the small amounts of fat-soluble fibers and phospholipids existed in carotenoid crystals before preparing for the oil suspension of carotenoid in order to decrease its viscosity and increase its fluidity, further to improve content of carotenoid in oil suspensions.